1. Field of the Invention
The present invention relates to an image pickup apparatus suitably used for a videoconference system, and an image processing apparatus for processing picked-up video images. The invention is also concerned with an image pickup system formed by connecting the above image pickup apparatus and the image processing apparatus.
2. Related Background Art
Hitherto, as a videoconference system using the above type of apparatus, conference-type large-sized cabinet-accommodated systems, and cart-type systems housed in a wheeled cart are the mainstream. Along with widespread use of computers (personal computers), desktop videoconference systems using personal computers have appeared and are currently in the limelight. This system is constructed, as illustrated in FIG. 10, of a video camera 101, an expansion board 102 for a personal computer (which incorporates sound and video images, performs data expansion and compression, and executes communication control), a headset 103, and software 104.
FIG. 11 is an external view illustrating the construction of a desktop videoconference system formed by connecting the above elements 101 through 104 to a personal computer. In FIG. 11, the system further includes the main unit 105 of the personal computer, a personal computer monitor 106, a keyboard 107, and a mouse 108.
Electrical connection of the above-described components is shown in FIG. 12. An explanation will now be given with reference to FIG. 12 of an example in which the communication camera VC-C1 (which was invented by the present inventor and became commercially available in 1994) is used as the video camera 101.
The video camera 101 is equipped with a pan-tilt mechanism, a video output, an S-video output, a sound line output, a direct-current (DC) power input, and an RS232C control terminal (none shown). For supplying DC power to the video camera 101, a DC power supply line (a DC power supply and a ground) 110 is first connected to the video camera 101 via an AC adapter 109. Among the video outputs of the video camera 101, for example, the S-video output terminal, is then connected to an S video input terminal provided for the expansion board 102 via a video cable 111. Subsequently, for controlling various functions of the video camera 101, such as pan, tilt, and zoom, an RS232C terminal of the personal computer unit 105 and an RS232C terminal of the video camera 101 are connected by the use of an RS232C cable 113. With respect to sound, since a microphone is not built into the video camera 101, a headset 103 having a microphone and a speaker is connected to the expansion board 102 using a headset cable 112.
In this manner, electrical connections with respect to (1) a video camera power supply, (2) video signals, (3) control signals, and (4) sound signals have been completed. After the personal computer is switched on, a predetermined software program is run to enable this system to function as a desktop videoconference system. Operation of the videoconference and connection of the system to a communication line, such as an integrated services digital network (ISDN), are irrelevant to the present invention, and an explanation thereof will thus be omitted.
The number of connecting cables used for establishing the above-described electrical connections can be summarized as follows:
(1) two power supply cables, i.e., a DC power supply and a ground (GND); PA1 (2) four video cables, i.e., Y and C video signal cables and the respective GNDs; PA1 (3) eight RS232C cables, (however, the minimum number in synchronous serial transmission is four, i.e., Tx, Rx, clock and GND); and between the headset 103 and the expansion board 102, PA1 (4) three headset cables, i.e., a microphone signal line, a speaker signal line, and a GND. PA1 (1) The three cables, such as the power supply cable 110, the video cable 111, and the RS232C cable 113 are separately connected to the video camera 101, thereby impairing the external appearance from an aesthetic point of view and also lowering reliability. In short, a disconnection of any one of the cables will spoil the operation. PA1 (2) The two cables, such as the video cable 111 and the headset cable 112, are also separately connected to the expansion board 102, thereby marring the external appearance of the back side of the personal computer unit 105 at which the connecting portions with the above cables 111 and 112 are disposed. PA1 (3) The RS232C cable 113 for controlling the video camera 101 is unfavorably connected to the RS232C terminal of the personal computer unit 105 which may be required for connecting to another device, for example, a modem or a printer. PA1 (4) The headset 103 is preferably disconnected and stored in, for example, a drawer when not in use from a sanitary point of view. The headset cable 112, however, is connected to the back side of the personal computer through the expansion board 102 and is not easy to disconnect. PA1 (5) The AC adapter 109 is not always coupled to the same AC power supply line as the line for the personal computer unit 105. It is thus necessary to check that power is positively supplied to the AC adapter 109 when AC power is supplied to the computer unit 105.
Accordingly, four types of cables and at least 13 signal lines are required in total.
However, the aforedescribed conventional system presents the following problems.